The included testcase demonstrates the ICE: aarch64_valid_floating_const (via aarch64_float_const_representable_p) disables HFmode immediates, but allows 0.0. However, *movhf_aarch64 does not allow this insn:
(insn 7 6 10 2 (set (mem:HF (reg/f:DI 73) [0 *f_2(D)+0 S2 A16]) (const_double:HF 0.0 [0x0.0p+0])) test.c:8 -1 (nil)) Fix is to allow the second operand to be zero, in the same way as *movsf_aarch64. Bootstrapped + check-gcc on aarch64-none-linux-gnu. New test also passing on arm-none-eabi. OK for trunk? gcc/ChangeLog: * config/aarch64/aarch64.md (*movhf_aarch64): Use aarch64_reg_or_fp_zero for second operand. gcc/testsuite/ChangeLog: * gcc.target/aarch64/fp16/set_zero_1.c: New. --- gcc/config/aarch64/aarch64.md | 2 +- gcc/testsuite/gcc.target/aarch64/fp16/set_zero_1.c | 22 ++++++++++++++++++++++ 2 files changed, 23 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.target/aarch64/fp16/set_zero_1.c diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md index 78b9ae2..8895a4e 100644 --- a/gcc/config/aarch64/aarch64.md +++ b/gcc/config/aarch64/aarch64.md @@ -1120,7 +1120,7 @@ [(set (match_operand:HF 0 "nonimmediate_operand" "=w, ?r,w,w,m,r,m ,r") (match_operand:HF 1 "general_operand" "?rY, w,w,m,w,m,rY,r"))] "TARGET_FLOAT && (register_operand (operands[0], HFmode) - || register_operand (operands[1], HFmode))" + || aarch64_reg_or_fp_zero (operands[1], HFmode))" "@ mov\\t%0.h[0], %w1 umov\\t%w0, %1.h[0] diff --git a/gcc/testsuite/gcc.target/aarch64/fp16/set_zero_1.c b/gcc/testsuite/gcc.target/aarch64/fp16/set_zero_1.c new file mode 100644 index 0000000..36cadfd --- /dev/null +++ b/gcc/testsuite/gcc.target/aarch64/fp16/set_zero_1.c @@ -0,0 +1,22 @@ +/* { dg-do run } */ +/* { dg-options "-O2" } */ +/* { dg-additional-options "-mfp16-format=ieee" { target "arm*-*-*" } } */ + +extern void abort (void); + +__attribute__ ((noinline)) +void +setfoo (__fp16 *f) +{ + *f = 0.0; +} + +int +main (int argc, char **argv) +{ + __fp16 a = 1.0; + setfoo (&a); + if (a != 0.0) + abort (); + return 0; +} -- 1.9.1